The escalating challenge of industrial dye pollution in wastewater necessitates the exploration of effective treatment methodologies. This study introduces a novel approach combining microwave irradiation with the Fenton oxidation process, showcasing a significant leap in the removal of Reactive Yellow 145 pollutants. By systematically manipulating variables such as Reactive Yellow 145 concentration, catalyst presence, and reaction environment pH, the investigation reveals a substantial increase in the degradation efficiency of complex dye molecules. The synergy between microwave energy and chemical oxidants under optimal conditions results in a remarkable reduction of both color and chemical oxygen demand (COD) levels, with the process achieving over 95% dye elimination and 82% COD reduction within 7 minutes. The analysis of UV-Vis spectroscopy before and after treatment showed that the microwave-enhanced Fenton process efficiently decomposed dye molecules, with a notably faster decomposition rate observed for azo and hydrazine groups compared to aromatic structures. This study not only underlines the potential of microwave-assisted Fenton processes in addressing persistent wastewater contaminants but also sets the groundwork for future research in scalable, environmentally friendly wastewater treatment solutions.

Background & Aims of the Study: Discharge of textile industry colored wastewater without enough treatment into natural water resources cause serious pollution. Most of the conventional wastewater treatment methods are not effective enough to remove these dyes from wastewater. In this study, efficiency of electrocoagulation process with iron electrodes for treatment of Reactive Yellow 14 dye from synthetic solution has been studied and concluded.Materials & Methods: This experiment was conducted in a batch system with a volume of 2 L that had been equipped with 4 iron electrodes. The effect of operating parameters, such as voltage, time of reaction, initial dye concentration, and interelectrode distance on the dye removal efficiency was investigated.Results: In optimum condition (pH 2, voltage 40 V, electrolysis time 25 min, and interelectrode distance 1 cm), electrocoagulation method was able to remove 99.27% of Reactive Yellow 14 from synthetic solution.Conclusions: Electrocoagulation process by iron electrode is an efficient method for removal of reactive dyes from colored solution.

Background and purpose: Chemical dyes used in textile industries involve some potential risks including carcinogenic and mutagenic effects in human. Furthermore, penetration of different dyes into surface and groundwater is a source of color in water reservoirs. This study aims at investigating the removal efficiency of yellow 3 and disperse yellow 3 reactive dyes by combined CAC-SBR system.Materials and methods: This experimental study was conducted on a batch scale and two SBR reactors were used. Wastewater samples used in this study were synthetic (COD=1800). After setting up the reactors, yellow 3 and disperse yellow 3 reactive dyes were injected to the system and its removal efficiency was investigated during different reaction times. After determining the SBR system efficiency in dye and COD removal, GAC-SBR system efficiency was examined.Results: During 24 hours of reactions, the efficiency of SBR and GAC-SBR systems in the removal of reactive yellow3 dye was 58% and 72%, while for disperse yellow 3 it was 85 and 91%, respectively. Also, during 14 hours of reaction, the efficiency of SBR and GAC-SBR systems for COD removal was 98 and 98.5%, respectively.Conclusion: The efficiency of GAC-SBR system in the removal of reactive yellow 3 and disperse yellow 3 dyes was higher than that of the SBR system. However, their difference was insignificant regarding the COD removal. Overall, increase in the reaction time led to increase in the efficiency of systems and in a specific time of the reaction, their removal efficiency became uniform.

This study investigates the efficacy of hydrogel nanocomposites as adsorbents for the removal of reactive yellow (RY) dye from aqueous solutions. Sodium montmorillonite (MMT) nanofillers were incorporated into poly N-isopropylacrylamide (poly (NIPAM)) and polyacrylic acid (poly (AAC)) hydrogels to create the nanocomposites. XRD, TGA, FTIR, and SEM techniques were used to characterize the resulting materials. The effects of several parameters on the adsorption process were comprehensively examined, including nanocomposite dose, solution pH, contact time, and initial dye concentration. The results showed that an acidic environment (pH < 7), with a contact time of 90 minutes and a dosage of 0.05 g of the nanocomposite, was optimal for achieving maximum adsorption capacity of RY dye. Poly (AAC) nanocomposites, poly (NIPAM) nanocomposites, and poly (NIPAM-co-AAC) nanocomposites showed the highest adsorption capacities of 168.3, 108.22, and 128.9 mg/g, respectively. The Langmuir and Freundlich isotherm models were used to fit the experimental data, with the Freundlich model demonstrating a superior fit. Kinetic studies further indicated that the dye adsorption process adhered to the pseudo-second-order kinetic model.

Background & Objectives: The widespread use of dyes leads to create problems such as environmental pollution in form of color wastewater discharges to environment and also lead to entering of color effluent into receiving waters. The dye lead to prevent of penetration of sunlight into water and thus photosynthetic processes in surface water were disordered. Therefore the aim of this study is determined the efficiency and effectiveness of magnesium oxide nanoparticles in removal of reactive yellow 3 dyestuff from aqueous.Materials and Methods: This study was experimental that effects of variables affecting on the efficiency of dye removal from synthetic wastewater was studied and survived effect of The parameters: pH (5, 7, 9), reaction time (30, 60, 90), adsorbent dose (0.1, 0.2, 0.3 g) and initial dye concentration (30, 50, 100, 150 mg/l).Results: The results showed that with increasing contact time, adsorbent concentration and color decreasing, removal efficiency increased, as The most efficiency of dye removal was obtained at Ph=7 (55%), adsorbent amount 0.3 g (96.36%), dye concentration 30 mg/l (86%), and contact time of 90 minute (62.2%).Conclusion: The efficiency more than 90% prepared absorbent in the removal of dyes from aqueous was shown that it can be used as adsorbent effective in treatment processes. So use this technique to remove colored contaminants from aqueous solutions have been proposed.

Background & Aims of the Study: Textile dyes generally are made of synthetic, organic, and aromatic compounds that may be contain of some heavy metals in their structure. Complex structure and presence of these metals cause toxicity and may be mutagen, teratogen or carcinogen. This study has investigated the ability of peanut shell powder to removal of some reactive dyes (Green 19, Orange 16, and Yellow 14) from aqueous solutions.Materials & Methods: The effects of contact time, initial concentration of reactive dyes, adsorbent dosage and pH have been reported. The applicability of Langmuir and Freundlich isotherm was tried for the system to completely understand the adsorption isotherm processes.Results: Batch adsorption studies showed that the peanut shell powder was able to remove the reactive dyes from aqueous solutions in the concentration range 25 to 250 mg/L. The highest percent removal for the Green 19, Orange 16, and Yellow 14 dyes was 84.2%, 87.36% and 88.49%, respectively. The adsorption was favored with maximum adsorption at pH=2. Also the optimum adsorbent dose was obtained 0.4 g/100 mL. By increasing adsorbent dose and initial concentration, removal efficiency was increased considerably. The adsorption isotherm studies clearly indicated that the adsorptive behavior of dyes on peanut shell satisfies only the Freundlich with average R2=0.926.Conclusions: Based on findings, the peanut shell powder was found as a low cost, natural and abundant availability adsorbent to removal of reactive dyes from aqueous solution.

In this research, the zinc–aluminum layered double hydroxide (Zn–Al LDH) was synthesized and structurally and morphologically characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and N2 adsorption–desorption techniques. The obtained nano-structured inorganic material was employed as an innovative nano-sorbent for separation of Reactive Yellow 84 (RY84) dye from aqueous solutions, which can be spectrophotometrically monitored at l=359 nm. The effect of several parameters such as type of interlayer anion in Zn–Al LDH structure, pH, sample flow rate, elution conditions, amount of nano-sorbent, sample volume and co-existing ions on the retention efficiency was investigated and optimized. The results showed that trace amounts of the RY84 could be retained using a column packed with 300 mg of the Zn–Al (NO3-) LDH at pH 8 and stripped by 2.5 mL of 3.0 mol L-1 NaOH. Under the optimum experimental conditions, the limit of detection and the relative standard deviation were 0.04 mg mL-1 and 1.8 %, respectively. The calibration graph using the presented solid phase extraction system was linear in the range of 0.15-1.5 mg mL-1 with a correlation coefficient of 0.9982. The method was successfully applied to removal of RY84 from several textile wastewater effluents.